Backyard Aquaponics
A place to discuss aquaponics

I'm concerned i bought the wrong chelated iron and seaweed from amazon. The iron has potash and nitrogen in it.... and the seaweed has Potash and chlorine in it. If they are right how much should i add? the seaweed also has iron in it aswell.


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Well the seaweed is fine but whether the iron in it will be usable to the plants will depend on the pH of your system water and/or how you apply it. The pH has to be low (I forget exactly where but pretty sure it's below pH 7) for the Ferrous Sulphate iron to be usable or you'll have to spray it onto the plants for it to work.

Maxicrop - Between .25 and .5 Oz per each 10 gallons for first dose then 1 Oz per 200 gallons every two weeks. Reduce or stop additions if deficiency symptoms go away.

For foliar feeding 1 Oz per gallon or about 30mls per 3.8 L then spray directly on plants.

The general consensus on the chelated iron seems to be that the Fe-DTPA is the one to get. There's another one that works but turns the water red, making it hard to read test results. This info might be helpful if you get the right stuff -

Chelated Iron - 1 level teaspoon per 1000L every 6 to 8 weeks if pH is above 7.0 and iron deficiency is indicated. Fe-DTPA is light sensitive probably best to apply just before dark (about 96 hours for >90% of Fe-DTPA to be destroyed with exposure to light of the wrong wavelength - usually precipitates out and becomes unavailable to the plants).

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Might want to watch this video by Nate Storey and the part 2 that goes along with it (very helpful and gives a good explanation) - https://www.youtube.com/watch?v=E4_hCAnymFw.

Cheers

So i followed your advice for the first time addition and it turned out pretty badly.

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I added 8.75 OZ for 250 gallons which is .35 OZ every 10 gallons Hopefully it will go away or i might need to completely change the water out.

Are you talking about the water color? That's normal when adding the iron it's much worse with the iron chelate that changes the water to red. It will go away but it takes a while. FYI - If I don't see any symptoms of Iron deficiency then I stop adding. Some people just add chelated iron on a regular basis but my feeling is that if the pH is low enough that regular iron can be used then some iron from other sources like feed (and rocks), is usable. If you want to avoid the water color change then use the spray method I listed (1 Oz per gallon or about 30mls per 3.8 L then spray directly on plants)